The Crown (5 shillings) is one of the few denominations with a gold and a silver equivilent struck at the same time. Ironically, this gold crown is more common and less expensive than its silver equivilent.
James I (VI of Scotland) was of course, the monarch who united the Crowns of England and Scotland, and was subject to the notorious gunpowder plot of the 5th of November 1605, in which the gunpowder plotters led by Robert Catesby (including a certain Guido Fawkes) planned to blow up the King along with his Parliament. This coin, part of his second coinage, with a lis mintmark was struck between 1604 - 1605, at around the same time as the gunpowder plot, and may even have been struck that very day.
The reverse legend is a reference to Henry VII's role in uniting the Houses of York and Lancaster and putting an end to the Wars of the Roses, as well as James' role in Uniting the Kingdoms. James was eager to see a united Britain, as can be seen as his obverse legend were he is described as 'King of Great Britain'. However, England and Scotland remained seperate Kingdoms during James' lifetime, and his efforts to unite the Parliaments of England and Scotland as well as the Crowns remained a frustrated ambition of his that was not fulfilled until the reign of his great-grandaughter Anne in 1707. A very interesting coin considering the historical context.

Obverse
First bust of king facing right, half length with decorated armour, mintmark lis.
JACOBUS.DG.MAG.BRIT,FRA.ET.HIB,REX (James by the Grace of God, King of Great Britain, France and Ireland)